For loop not starting at 1

Hi guys, I am trying to run a loop of an image which finds the max value and then used that value Max1 to then get a normalised signal however if l1 doesnt start at 1, the normalisation doesnt work and a much larger value occurs in the very first number of l

if true
 figure(p+3);
l1=7
l2=17
for l=l1:l2
  Cr1=[1 (VerticalBurnerStart+(l*(y2/Res))) x-1 y2/Res]; 
  Cr = imcrop(YourData, Cr1);  
  T{l}=mean(Cr).';         % Find the mean of each column in array     
K3= plot(x2,T{l},'DisplayName',['HAB= ' num2str(l)]);
Max(l)=(max(unique(T{l})));
hold on 
end
legend(gca,'show');
Max1=max(Max);
end

Answer 1

[Thorsten]

If you set Max(7) = something, values Max(1) til Max(6) are set to zero if Max does not exists, or it keeps the values in Max(1) til Max(6) from previous runs.